高速光导入太赫兹扩频通信系统理论与实验研究

In recent years, demand for bandwidth of wireless communication is growing. Compared with microwave communication, terahertz communication has wider bandwidth due to its high frequency properties，and it has many excellent wireless transmission characteristics, such as well-orientation and high security. Therefore, integration of optical fiber communication and terahertz wireless communication technology has broad application prospects. Main work in this project will surround exploiting spectrum resources and high bandwidth, to modulate the data from optical network with terahertz wave by harmonic mixing circuit. Research work also includes THz emission, transmission, detection and signal demodulation. Aiming at the situation of shortage of new modulation types, coding means and mechanisms of interference suppression for terahertz communications, researching contents include analysis of terahertz wave propagation model and time-frequency interference with dynamic parameter under complex environment, adaptability to terahertz wireless Channel, system noise, interference source and anti-multipath-fading,etc. Experiment system will be built to validate the feasibility of research plan, this project will also be the theoretical and technical reserves for terahertz wireless communication of individual broadband wireless access and indoor communication systems.

近年来，用户对无线通信带宽的需求日益增长。同微波通信比较，由于太赫兹波的高频属性使太赫兹通信具有更宽的带宽，同时其具备方向性好、安全性高等许多无线传输特性,因此将骨干网的光纤通信与太赫兹无线通信技术的融合具有广阔的应用前景。本项目将围绕“开拓频谱资源”和“超高带宽”两大诉求开展将核心光网络的数据信号进行宽带太赫兹无线传输的研究工作，重点研究采用次谐波混频电路实现太赫兹波的数据调制、发射、空间传输与解调等问题。针对太赫兹通信的干扰抑制机理及调制编码新手段的研究成果不足现状，研究内容包括：复杂环境下动态参量的太赫兹波传播模型与时频干扰特征分析，太赫兹物理信道的适应性研究，系统噪声及干扰来源探索和抗多径衰落研究等工作，并进行实验系统搭建和方案验证，为太赫兹频段面向个人的超宽带无线接入和高速室内覆盖等应用进行理论储备。

随着5G的正式投入商用和6G白皮书的发布，6G成为了研究的热点，太赫兹通信技术将是6G实现的关键技术。设计、仿真并集成了310GHz固态电子太赫兹通信系统，对系统进行了关键指标的测试，此系统可在1m的距离实现10Gbps无误码的传输；基于此系统研究了湿度、烟对太赫兹通信指标的影响，发现水蒸汽对太赫兹波有较大的吸收，导致眼图恶化，烟的影响较小；设计了光纤导入的太赫兹通信系统并验证了可行性，对于未来太赫兹通信远距离传输提供了参考。基于射线追踪法对会议室场景进行了信道建模，并计算出了莱斯K因子、均方根时延扩展等信道参数，发现信道参数主要取决于Rx的位置，为室内太赫兹信道的研究提供了参考模型。通过仿真把直接序列扩频通信技术应用到太赫兹波段来抑制多径效应，发现误码率有了明显下降，这项技术可应用到未来的太赫兹通信中。